[Twisted-Python] adbapi transaction initiation

[Landreville]

I've just noticed the transaction_timestamp is actually way (up to
several minutes) before the database proc gets called. I'm on
postgresql 8.4 so the transaction_timestamp is when the transaction
started, and I compared it against the clock_timestamp (absolute
current time) and it is quite a bit off.

Does adbapi start transactions before any method (ie runQuery) is called?

Or should I be looking at the underlying database driver to this behaviour?